THE CRANE-FLIES OF NEW YORK PART II 803 



Antocha is by no means confined to rapidly flowing streams, altho 

 the insects are very often found in such situations. The writer has found 

 adults in his tent traps set over the Sacandaga River, in Fulton County, 

 New York, where the water was very quiet and at least ten feet deep. 

 Needham (1908 a: 169-170, 205), similarly, found adults in numbers in 

 his tent traps set over Beaver Meadow Brook at Old Forge, New York, 

 in August, 1905, but did not locate the larvae. In rapid-flowing streams 

 the insects sometimes occur just at the surface in a few millimeters of 

 water, or at greater depths. The immature stages seem adapted to live 

 under almost any conditions of current, from moderate pressure to sit- 

 uations where the water rushes by in torrents and where but few of the 

 usual lotic organisms, such as Blepharocera, Simulium, Psephenus, and 

 others, can exist. From Clemens' studies (1917:14-23) it is evident that 

 the current is much more rapid just beneath the surface than at various 

 lower depths, so that at a depth of one foot the current velocity is only 

 about two-thirds of that at the surface. Thus these aquatic organisms are 

 not constantly and entirely subjected to such tremendous pressures as 

 on first sight they appear to be. Many of the larvae and pupae perish 

 from desiccation, due to the lowering of the stream level and the conse- 

 quent exposure of the rocks on which their homes are made. 



Copulation between the adult flies takes place on the exposed rocks 

 in and along the margins of the streams where the larvae live (Osten 

 Sacken, 1869:127). The eggs are deposited in the water, and the entire 

 life, until the emergence of the adult fly, is spent beneath the water. The 

 whole life cycle may require a year, altho the species is possibly double- 

 brooded. At a single time, and even on a single rock, larvae of various 

 sizes, from very small ones to those almost fully grown, may be found, 

 and this probably explains the long flight-period of the adult. That the 

 species is double-brooded remains to be proved. 



The food of the larva consists of microscopic plant organisms in the 

 water, the curious maxillae, with their dense brushes of long hairs, 

 undoubtedly being an adaptation for this type of food. 



Larva. Total length, 9.5-10.5 mm. 



Length of caudal lobes alone, 1.1-1.2 mm. 

 Diameter of body, 1-1.1 mm. 



Coloration of living larva, light greenish brown above, clearer greenish ventra ] ly; contents 

 of alimentary canal showing clearly thru the thin skin; on segments 7 and 8, two paired, bright 



